Termites feed upon wood, including structural wood that is either in contact with soil or is in close proximity to soil. Subterranean termites have very little resistance to dehydration and nest in the soil to obtain needed moisture. Subterranean termites build shelter tubes, also known as mud tubes, to travel between the soil and a food source that is nearby but not in direct contact with the soil. These shelter tubes provide a dark, moist environment that protects the termites from sunlight, temperature extremes and attack by predators.
To prevent termite damage termiticides such as permethrin, cypermethrin and bifenthrin, are applied to the soil under and around dwellings as a chemical barrier. For new construction, this is accomplished by applying large amounts of the diluted termiticides to the graded soil before the pouring or construction of the building foundation. For an effective treatment, timing of the treatment is important as not to disturb the barrier formed in the soil. Typically the appropriate application time window is narrow and, in the case of multiple dwelling constructions, the application time does not occur simultaneously. Multiple visits by the applicator may be required in these circumstances as well as the transportation of large quantities of water required to dilute the insecticide/termiticide for application.
For existing buildings, the perimeter of the foundation is trenched and drilled then injected with large quantities of the diluted insecticide/termiticide. Special digging, drilling, mixing and pumping equipment is necessary for treating existing buildings. Applying a perfect barrier is difficult in that gaps or breaks in the barrier due to rain or some other form of physical activity, for example, digging, walking or pipe laying, may disturb the barrier. Termites are able to detect the termite barrier termiticide in the soil and avoid lethal contact. Eventually, foraging termites may locate barrier gaps and gain access into the structure. If these termites find structural wood, they will tunnel back through the barrier gap and recruit other termites into the building.
Another approach to termite control is to apply a termiticide material onto pre-construction wood through spray or spray/vacuum applications. The pyrethroid bifenthrin is used for treating framing timber for use in floor frames, wall frames, roof trusses and subflooring. Although this approach to termite control is effective, it requires the use of expensive application equipment. In addition, timber treated with bifenthrin must be handled very carefully, for example, workers should wear gloves and respirators when cutting, sanding or drilling treated wood. Resealing treatments are required when treated wood is rip sawn, redressed or has the original dimensions significantly altered. Off-cuts, saw dust and general waste from bifenthrin treated wood must not be burned or allowed to enter sewers, drains, dams, or other water ways due to the toxicity of bifenthrin to aquatic organisms thus requiring waste to be placed into containers and disposed of in approved landfills.
Borate compounds have been used in the preventative and/or pretreatment of structures to control subterranean termites. Commercial products that contain borates, for example, BORA-CARE® Termiticide, Insecticide and Fungicide Concentrate available from Nisus Corporation, which contains disodium octaborate tetrahydrate, are toxic to termites only by ingestion. Since termites must ingest the borate compound, a band of at least two feet must be applied in order to ensure that the termites obtain a toxic dose and significant damage to the wooden and cellulose materials in man-made structures can occur before the termites are eradicated. In addition, termites can construct shelter tubes over the borate treatment to reach untreated wood and cellulose containing materials.
Therefore, there exists a need for a safe, inexpensive, easy to use and environmentally friendly way of protecting man-made structures and cellulose materials contained in the structure from subterranean termite damage.